User Interface or UI programs enable interaction between users and application programs running on computers. There is a wide variety of user interfaces with different approaches in interaction and design.
Modern business applications are usually web based and typically a web browser is used to display and enable one or more web pages utilizing a user interface.
For business applications, web pages can be seen as the union of business data and user interface layout settings. The business data are retrieved for every application from one or more backend systems. There may be different backend systems for different applications, like Supply Chain Management (SCM), Customer Relationship Management (CRM), Financials (FI), etc. The business data are organized in the web page according to the user interface layout settings.
For web pages with dynamic screen content, a server side scripting language is commonly used. The server side scripting language may include, but is not limited to, Java Server Pages (JSP), Active Server Pages (ASP) and/or Business Server Pages (BSP). However, the straightforward use of a server side scripting language will typically result in a solution that fits only the application it was originally intended for, because there is no standard way of treating the user interface layout and the specialized tags provided by a reusable tag library.